Method for selecting cell by multi-mode wireless terminal

Abstract

The invention discloses a method for selecting a cell by a multi-mode wireless terminal. In a cell reselection process, the multi-mode wireless terminal firstly divides a cell which is in accordance with a cell selection standard S into a preferential network mode cell and a suboptimum network mode cell, and then a finally reselected target cell is determined by using fuzzy reasoning and fuzzy decision methods, wherein in a plurality of pilot frequency cells, participating reselection, with same frequency and same priority, fuzzy reasoning is utilized to evaluate five measurement parameters, namely, a receiving level value of each cell, a minimum required receiving level value in the cells, relative frequency shift, available uplink maximum transmitting power of a terminal and maximum radio frequency output power of the terminal, then, the requirements of a user on transmission rate and service instantaneity are integrated, an optimal target cell is selected according to a fuzzy decision result, and then the terminal is switched to the cell for residing. According to the method, the time of the switching process is short, seamless transition can be realized, user calls can be avoided being lost, a user is ensured to reside in the cell with the optimal service quality, and furthermore, the risk of missing the call during manual mode switching is eliminated.

Description

Technical field [0001] The present invention relates to a method for a multi-mode wireless terminal to perform cell selection, specifically, to a method for a multi-mode mobile terminal to perform cell reselection when there are multiple cells to be selected; it belongs to the technical field of cell selection for wireless mobile terminals . Background technique [0002] With the continuous development of wireless communication technology, the second generation mobile communication system (2G) and the third generation mobile communication system (3G) will coexist for a long time. Especially in hotspots, the networks of the three 3G systems (TD-SCDMA, WCDMA and CDMA2000) and the traditional 2G system (GSM and CDMA) will also overlap in many areas. How can user terminals better adapt to the current situation of overlapping coverage of communication networks? Reselect cells between different systems to ensure that dual-mode terminals can adaptively choose among multiple network mod...

AI Technical Summary

Problems solved by technology

Due to the small number of parameters considered, the terminal cannot meet the requirements of the coexistence of real-time services, non-real-time services, multimedia services, and voice services under multi-mode conditions

[0016] (2) The complexity of reselection processing is high: the existing cell reselection standard is to sort all the cells according to the network priority, and then according to the network priority, the same frequency and the same priority different frequency cell reselection criteria Rs and Rn Complete the ranking of the neighborhoods and re-select to the first ranked neighborhood

However, the complexity of sorting all cells is high, which not only increases the complexity of the terminal, but also increases the handover time

Especially when there are multiple modes and a large number of cells, the long switching time due to complex operation will increase the probability of user dropping calls and being unable to connect

[0017] (3) The linear evaluation strategy adopted for cell reselection is unreasonable: the existing evaluation mechanism for cell reselection considers all parameters according to a fixed ratio

However, the multi-mode mobile terminal system is complex, and there are many parameters to be considered when determining cell handover. It is often difficult to reselect to a cell that meets the user's rate and real-time requirements according to the fixed linear theoretical model and policy criteria, causing users to often drop calls Or real-time business interruption, reducing the quality of service

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